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-rw-r--r--arch/x86/include/asm/sync_bitops.h118
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/x86/include/asm/sync_bitops.h b/arch/x86/include/asm/sync_bitops.h
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+++ b/arch/x86/include/asm/sync_bitops.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_SYNC_BITOPS_H
+#define _ASM_X86_SYNC_BITOPS_H
+
+/*
+ * Copyright 1992, Linus Torvalds.
+ */
+
+/*
+ * These have to be done with inline assembly: that way the bit-setting
+ * is guaranteed to be atomic. All bit operations return 0 if the bit
+ * was cleared before the operation and != 0 if it was not.
+ *
+ * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
+ */
+
+#include <asm/rmwcc.h>
+
+#define ADDR (*(volatile long *)addr)
+
+/**
+ * sync_set_bit - Atomically set a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * This function is atomic and may not be reordered. See __set_bit()
+ * if you do not require the atomic guarantees.
+ *
+ * Note that @nr may be almost arbitrarily large; this function is not
+ * restricted to acting on a single-word quantity.
+ */
+static inline void sync_set_bit(long nr, volatile unsigned long *addr)
+{
+ asm volatile("lock; " __ASM_SIZE(bts) " %1,%0"
+ : "+m" (ADDR)
+ : "Ir" (nr)
+ : "memory");
+}
+
+/**
+ * sync_clear_bit - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * sync_clear_bit() is atomic and may not be reordered. However, it does
+ * not contain a memory barrier, so if it is used for locking purposes,
+ * you should call smp_mb__before_atomic() and/or smp_mb__after_atomic()
+ * in order to ensure changes are visible on other processors.
+ */
+static inline void sync_clear_bit(long nr, volatile unsigned long *addr)
+{
+ asm volatile("lock; " __ASM_SIZE(btr) " %1,%0"
+ : "+m" (ADDR)
+ : "Ir" (nr)
+ : "memory");
+}
+
+/**
+ * sync_change_bit - Toggle a bit in memory
+ * @nr: Bit to change
+ * @addr: Address to start counting from
+ *
+ * sync_change_bit() is atomic and may not be reordered.
+ * Note that @nr may be almost arbitrarily large; this function is not
+ * restricted to acting on a single-word quantity.
+ */
+static inline void sync_change_bit(long nr, volatile unsigned long *addr)
+{
+ asm volatile("lock; " __ASM_SIZE(btc) " %1,%0"
+ : "+m" (ADDR)
+ : "Ir" (nr)
+ : "memory");
+}
+
+/**
+ * sync_test_and_set_bit - Set a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.
+ * It also implies a memory barrier.
+ */
+static inline bool sync_test_and_set_bit(long nr, volatile unsigned long *addr)
+{
+ return GEN_BINARY_RMWcc("lock; " __ASM_SIZE(bts), *addr, c, "Ir", nr);
+}
+
+/**
+ * sync_test_and_clear_bit - Clear a bit and return its old value
+ * @nr: Bit to clear
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.
+ * It also implies a memory barrier.
+ */
+static inline int sync_test_and_clear_bit(long nr, volatile unsigned long *addr)
+{
+ return GEN_BINARY_RMWcc("lock; " __ASM_SIZE(btr), *addr, c, "Ir", nr);
+}
+
+/**
+ * sync_test_and_change_bit - Change a bit and return its old value
+ * @nr: Bit to change
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.
+ * It also implies a memory barrier.
+ */
+static inline int sync_test_and_change_bit(long nr, volatile unsigned long *addr)
+{
+ return GEN_BINARY_RMWcc("lock; " __ASM_SIZE(btc), *addr, c, "Ir", nr);
+}
+
+#define sync_test_bit(nr, addr) test_bit(nr, addr)
+
+#undef ADDR
+
+#endif /* _ASM_X86_SYNC_BITOPS_H */